iSyi.] 



CANNELL'S PATENT BOILER. 



373 



Nos. 4 and 5, which form respectively the back and front of the apparatus, may 

 be flush with the ends of the first castings. The back or No. 4 casting is large 

 enough to cover the whole or part of the end of the apparatus, and is connected 

 at the bottom by pipes with castings Nos. 2 and 3 respectively, and at the top 

 on each side with casting No, 11, which will be afterwards described. The front 

 casting, No. 5, must be of such a height that the top will be level with the top of 

 No. 6, forming the top of the furnace. 



The front is built up with brickwork, with three sliding soot-doors to allow 

 the flues to be properly cleaned out. This front or No. 5 casting is connected at the 

 bottom by pipes with castings Nos. 2 and 3, and at the top on each side with 

 casting No. 6. Upon the top of castings Nos. 2 and 3 is placed a sixth further 

 and separate hollow fluted casting, forming the top of the furnace, having a space 

 left at the back opening upwards to allow a free passage for the fire to pass out 

 of the furnace under a separate and a hollow casting (No. 7), which, when fixed, 

 forms flues communicating by means of other flues formed by similar castings, 



'Boiler, 



and terminating in a rectangular opening at the top for regulating the draught, 

 and for the passage of the smoke into the chimney. 



The circulation of the water from and into every separate hollow casting is 

 effected by means of four sets of pipes affixed externally to the castings — two sets 

 being placed on each side of the apparatus. If desired, the crown or top casting 

 with the flow-pipe can be placed upon No. 2 or 3 casting, and worked without 

 the flues until required. 



The flame or hot air from the fire placed on the hollow bars will pass between 

 castings Nos. 2 and 3 until it arrives at the opening described, to be left at the back 

 casting No. 6, where it will pass upwards towards the front through the flues 

 formed by casting No. 7. It will then return towards the back through the flues 

 formed by casting No. 8, again uniting and passing upwards into the flues formed 

 by castings Nos. 9 and 10, the heat thus continuing to travel through castings 

 Nos. 9, 10, and 11 in the same way, so that the hot air will pass six times through 

 the internal length of the apparatus before escaping into the chimney. 



